Multi-Level Converter Gate Driving for EMI-Loss Balance

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Solution Overview

Problem

Existing gate driver systems for multi-level converter systems face a trade-off between switching losses and electromagnetic interferences, with fast switching reducing losses but increasing noise, and slow switching reducing noise but increasing losses, necessitating the use of filtering means.

Innovation Solution

The method involves using two subsets of gate driver units with different switching speeds, where one subset operates switching modules at a fast speed to minimize losses and the other at a slow speed to minimize noise, allowing for a balanced trade-off between switching losses and electromagnetic interferences without the need for filtering means.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of energy

If fast switching is used for switching modules, then switching losses are reduced, but electromagnetic interferences increase

Engineering Contradiction:
Improveswitching lossesVSAvoidelectromagnetic interferences
Core Design Contradiction:
Loss of energyVSObject-generated harmful factors

Solution Approach 1:

The gate driver system is segmented into multiple gate driver units (at least two) that can be independently controlled. Each gate driver unit operates switching modules at different switching speeds, allowing the system to distribute switching operations across multiple units with different speed characteristics, thereby reducing both switching losses and electromagnetic interferences simultaneously

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Different gate driver units are assigned different local qualities in terms of switching speed characteristics. At least one gate driver unit operates at a first switching speed while another operates at a second switching speed, enabling localized optimization where fast switching reduces losses in certain modules while slow switching reduces emissions in others

Inventive Principle:
Principle #3Local quality

2Object-generated harmful factors

If slow switching is used for switching modules, then electromagnetic interferences are reduced, but switching losses increase

Engineering Contradiction:
Improveelectromagnetic interferencesVSAvoidswitching losses
Core Design Contradiction:
Object-generated harmful factorsVSLoss of energy

Solution Approach 1:

The gate driver system is divided into multiple independently controllable gate driver units, each capable of operating at different switching speeds. This segmentation allows the system to assign slow switching to specific units for reduced electromagnetic interferences while maintaining fast switching capability in other units to minimize switching losses

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Different gate driver units are configured with different local quality characteristics regarding switching speed. Some units operate slowly to reduce electromagnetic interferences in specific regions or time periods, while other units operate quickly to minimize switching losses, achieving local optimization of both parameters

Inventive Principle:
Principle #3Local quality

3Object-generated harmful factors

If filtering means are added to reduce electromagnetic interferences, then electromagnetic interferences are reduced, but device complexity increases

Engineering Contradiction:
Improveelectromagnetic interferencesVSAvoidfiltering means
Core Design Contradiction:
Object-generated harmful factorsVSDevice complexity

Solution Approach 1:

The patent extracts and eliminates the need for filtering means by using a different approach - controlling the switching speed of gate driver units directly. Instead of adding filtering components to suppress electromagnetic interferences, the system achieves emission reduction through intelligent speed control of switching operations, thereby removing the complexity of filtering hardware

Inventive Principle:
Principle #2Taking out (Extraction)

Data Source

PatentEP4376280A1Method for operating a gate driver system for a multi-level converter system, data processing apparatus, computer program, computer-readable storage medium, gate driver system, multi-level converter system, and vehicle
Publication Date: 2024.05.29 VOLVO CAR CORP
  • EP4376280A1 patent drawingFigure 1~3
  • EP4376280A1 patent drawingFigure 4~5
  • EP4376280A1 patent drawingFigure 6~7

AI summary

The disclosure relates to a method for operating a gate driver system (20) for a multi-level converter system (14). The multi-level converter system (14) has a number of cascaded switching modules (24, 26, 30, 32). The gate driver system (20) comprises at least two gate driver units (36, 38, 40, 42), each being configured to operate an associated switching module (24, 26, 30, 32). The method comprises providing at least a first subset (A) and a second subset (B) of gate driver units (36, 38, 40, 42) and assigning a first switching speed to the gate driver units (36, 38, 40, 42) of the first subset (A) and a second switching speed to the gate driver units (36, 38, 40, 42) of the second subset. A first switching control signal is provided to the switching modules (24, 26, 30, 32) being associated with the gate driver units (36, 38, 40, 42) of the first subset (A) and a second switching control signal is provided to the switching modules (24, 26, 30, 32) being associated with the gate driver units (36, 38, 40, 42) of the second subset (B). Moreover, a corresponding data processing apparatus (44), computer program (52), and computer-readable storage medium (50) are described. Furthermore, a gate driver system (20), a multi-level converter system (14), and a vehicle are presented.